Wednesday, June 21, 2017

The UK Election Dot Map

The Colours of the Election is a dot map which provides a view of the geographical distribution of votes cast in the 2017 UK election. Each dot on the map represents 250 votes for one of the political parties. The dots are randomly distributed within each electoral area.

At the electoral ward level a random distribution of colored dots is obviously not the best way to present the number of votes cast for each political party. This data would be much more legible visualized as a bar graph. In fact randomizing the numbers within each constituency could be confusing as it suggests that the data is shown geographically - when in fact the data is just randomly distributed.

When you view the data at a regional level the data does begin to make more sense and the geographical distribution of votes for each political party can begin to emerge from the map. For example the regional view of London shows the dominance of Labour in inner London. The Conservatives voters are more concentrated in a ring in the suburbs outside of the center. This ring is broken in the south-west where the Liberal Democrats have a small pocket of support.

The question remains about whether this dot map view shows a more detailed picture of the number of votes cast for each party than a traditional election map. Here's the Evening Standard's static map of the 2017 election results in London.

I would argue that the Evening Standard map is at least as good, if not better, at showing where the different parties have the most support in London. In fact you could easily add a more refined analysis to the Evening Standard map by adding pop-up bar charts showing the total number of votes cast for each party in each electoral district.

What I do like about the Colours of the Election map is the responsive bar chart. This graph shows the total number of votes cast for each party for the current map view. This means that you can zoom and pan the map to explore the number of votes cast for each of the political parties in different parts of the UK. The date control also allows you to make a useful comparison between the support for each of the parties in this election and in previous elections.